In addition to glutamine, there has been interest in determining the role that other nutrients may have on immune function. From these studies, there appear to be several nutrients and or herbs that may help athletes maintain a healthier immune system during training. The first nutrient reported to enhance immune function is protein Studies indicate that immunosuppressed patients are often protein malnourished. Additionally, athletes who maintain a negative energy balance during training may also be susceptible to become protein malnourished. Protein supplementation in protein-malnourished patients has been shown to improve immune status Consequently, it is important that athletes eat enough quality protein in their diet to maintain a healthy immune system.
The second nutrient that may affect immune responses during training is vitamin C. Vitamin C is involved in the synthesis of epinephrine, iron absorption, and is an antioxidant. There is also evidence that vitamin C may enhance immune function. With regards to athletes, vitamin C supplementation (600 mg/day for 3 weeks) following an ultramarathon race was found to decrease the incidence of URTI by 33% following the event in comparison to athletes given a placebo These findings have led some to contend that athletes engaged in intensified periods of training should supplement their diet with vitamin C to help decrease the incidence of URTI.
More recently, zinc supplementation (25 to 100 mg/day) during the onset of symptoms of a cold or URTI has been reported to decrease the severity and length of the cold infection. Athletes have been reported to be commonly zinc deficient. Theoretically, zinc supplementation during intensified periods of training and or as athletes experience symptoms of a cold may help athletes stay healthier. To support this theory, one study reported that zinc supplementation (25 mg/day) during training minimized exercise-induced changes in immune function. However, more research is needed to test this hypothesis.
The last supplement that may be beneficial for athletes to enhance immune function is echinacea. Echinacea is a popular herb that has been reported to enhance the immune system in a similar manner as an antibiotic. Evidence suggests that echinacea can reduce the incidence, severity, and duration of colds and infections Theoretically, echinacea supplementation during periods of intensified training and/or as an athlete experiences symptoms of a URTI may help athletes stay healthy during training. However, although there is scientific support for use of echinacea, we are not aware of a study that has evaluated whether echinacea supplementation during training affects the incidence of URTI in athletes.
bodybuilding, c vitamin, immune status, immunosuppressed patients, Nutrition, protein studies, protein supplementation, symptoms of a cold, vitamin c
